1. Field of the Invention
The present invention relates to a telescopic tube, especially to a quick-acting telescopic tube that can support a musical instrument.
2. Description of the Prior Arts
With reference to FIG. 6, a conventional telescopic tube comprises a tube assembly (60), a lock activating assembly (70) and a locking assembly (80).
The tube assembly (60) comprises a stationary tube (61), a plug (62), a locking rod (63), an extension tube (64) and an activating tube (65).
The stationary tube (61) has a bottom. The plug (62) is mounted in the bottom of the stationary tube (61). The locking rod (63) is mounted in the stationary tube (61), is attached to the plug (62) and has multiple locking notches (631). The locking notches (631) are formed separately in the locking rod (63).
With further reference to FIG. 7, the extension tube (64) is mounted slidably in the stationary tube (61) and has a top end, a bottom end, a through hole (641) and an elongated through hole. The through hole (641) is formed transversely through the extension tube (64) near the top end. The elongated through hole is formed longitudinally near the bottom end.
The activating tube (65) is mounted slidably in the extension tube (64) around the locking rod (63) and has a top, a fastening hole (651), a mounting slot, a drive-pin hole and a drive pin (652). The fastening hole (651) is formed transversely through the activating tube (65) near the top. The mounting slot is formed longitudinally through the activating rod (65), communicates with the top and has a bottom end. The drive-pin hole is formed transversely through the activating tube (65) near the bottom end of the mounting slot. The drive pin (652) is mounted in the drive-pin hole.
The lock activating assembly (70) comprises a sleeve (71), a fastening pin (72), a spring (73) and a lever (74). The sleeve (71) is mounted securely around the extension tube (64) and has a through hole and a bracket (711). The through hole is formed through the sleeve (71) and aligns with the through hole (641) in the extension tube (64). The bracket (711) is formed on the sleeve (71). The fastening pin (72) extends through the aligned through holes (641) in the extension tube (64) and the sleeve (71). The spring (73) is attached to the fastening pin (72) and to the top of the activating tube (65). The lever (74) is L-shaped, is mounted pivotally in the bracket (711) and has a longitudinal arm (741) and a transverse arm (742). The longitudinal arm (741) pivots in the bracket (711). The transverse arm (742) connects to the longitudinal arm (741), extends into the mounting slot in the activating tube (65) and has an elongated drive-pin hole (743) formed through the transverse arm (742). The drive pin (652) is mounted through the drive-pin hole in the activating tube (65) and the elongated drive-pin hole (743) in the transverse arm (742).
With further reference to FIG. 8, the locking assembly (80) comprises a locking sleeve (81) and a clamp (82).
The locking sleeve (81) is mounted around the extension tube (64), connected to the activating tube (65) and has a pin (811), a bottom hole and a conical interior surface (812). The pin (811) is mounted through the locking sleeve (81), the elongated hole in the extension tube (64) and the activating tube (65) to slide the locking sleeve (81) on the extension tube (64) when the lever (74) on the lock activating assembly (70) is pressed or released. The conical interior surface (812) is formed adjacent to the bottom hole.
The clamp (82) connects pivotally to the extension tube (64), engages the conical interior surface (812) when the lever (74) on the lock activating assembly (70) is released and has two wings (821), a spring (822) and two latch pins (823). The wings (821) are semicylindrical and are attached pivotally to the bottom end of the extension tube (64). Each wing (821) has a proximal end, a distal end and a tapered head. The proximal end is attached pivotally to the bottom end of the extension tube (64). The tapered head is formed at the distal end and has a transverse latch pin hole. The tapered heads are pressed toward each other when the lever (74) on the lock activating assembly (70) is released. The spring (822) is mounted between the tapered heads of the two wings (821) and presses the tapered heads apart when the lever (74) on the lock activating assembly (70) is pressed and pushes the locking sleeve (81) down. The latch pins (823) are mounted respectively in the latch pin holes in the heads of the wings (821) and selectively engage locking notches (631) on the locking rod (63) when the conical interior surface (812) on the locking sleeve (81) presses the wings (821) together.
When the latch pins (823) engage the locking notches (631), the extension tube (64) is locked in place relative to the stationary tube (61).
However, the conventional telescopic tube is more expensive because the conventional telescopic tube comprises many components, and the components are complicated.
To overcome the shortcomings, the present invention provides a quick-acting telescopic tube with simple and fewer components to mitigate or obviate the aforementioned problems.